Pyrrolidone deicer in gasoline fuels



As is.well known to generally occurs higher, up to 100 percent.

ice builds upin the tube and restricts the Q 250 F. and about 450 I V 2,978,303 PYRRQLIDONE DEICER IN GASOLINE FUELS Myron Becker, Woodbury, N.J., assignor to Socony Mobil Oil Company, Inc., a corporation of New York a No Drawing. Filed Jan. 5, 1959, Ser. No. 784,896

2 Claims. 01.44-63 {stalling .of automobile -engines, especially during the warmup..period, has been a common occurrence. This difiiculty is most pronounced in postwar cars having automatic transmissions and a consequent limit on the maxifrnum permissible idle speed, although'it also occurs in cars without'autornatic transmissions. Stalling of this type,-of course, is a definite safety hazard, as well as a' decided, inconvenience engine. t

It is now recognized that stallingduring. the war'mup period is attributable to the formation of ice on the throttle plate and the carburetor barrel near it. which forms the ice does not come fromthe gasoline, i.e., as entrained Water, but from the air that enters the carburetor. ,As, has been mentioned hereinbefore, stalling in coohhumid weather, when the temperatures are above about 30 F. and below about 60 Rand the relative humidity is about 6 percent and .The most critical conditions are temperatures of 3540 humidity. v a

As the gasoline evaporates in thecarburetor, it re- .in frequent restarting of the .duces that temperature of the surrounding metal by as much as 40 F. Moisture in the incomingair comes in contact with these parts and begins to build. up icefon the throttle plate and in the carburetor barrel. The -more moist this air is,.-the greater the buildupof ice. Then, when the engine: is idl'edfthe throttle plate closes and the ice chokes otf the norrnalsmallflow'of airjthrough the small clearance between t-li'e throttle-'plate and the car buretor wall.

, canvusually-be restarted when the heat from manifold melts the icesufiicientlyr However,

Thiscauses the engine to stall. The engine 4 stalling will continue until the engine is completely'warmed up.

Icing may also occurjin the carburetor of-some vehicles when cruising .at speeds of 30-60 m.p.h. Such 'carburer thoseskilled in the art, frequent F. and 100 percent relative United States Patent 0 2,978,303 Patented Apr. 4, 1961 2 boiling point (e.g., full boiling range gasolines) can induce stalling when the aforementioned stall-inducing atmospheric conditions are prevalent. Thus, any gasoline will give difiiculty in damp, cool weather. In modern engine operation, however, control of stalling by means'of volatility is not'feasible, because other performance characteristics are affected. It has nowbeen found that stalling during engine warming up can be overcome simply and economically. It has been discovered that small amounts of 2-pyrrolidone, when added to motor gasoline, will overcome stalling diificulties attributable to carburetor icing. I

Accordingly, it is an object of this invention to provide an improved motor fuel. Another object isto provide a motor fuel adapted to prevent stalling during engine operation in cool, humid-weather. A specific object is to provide an antistall gasoline containing Z-pyrrolidone. Other objects and advantages of this invention will become apparent to those skilled in. the art, from the following detailed description.

In general, this invention provides a motor gasoline containing a small amount, suflicient to inhibit stalling, of 2-pyrrolidone. 1

The addition agent found effective herein is 2-pyrrolidone, a compound having the structure,

HAD- CH2 a This compound can be prepared by methods well known in The water I solvent oil or upperlube' the exhaust tors are found in trucks andYin many European'cars. The

flow of air, thereby enriching the fuel mixture and reducing eiiiciency.

hydrocarbons having an inigasoline, of course, reflects onitsvolatility. Thus, a

higher .boiling gasoline will be less volatile and give less stalling difliculty. It has been proposed in the art that a gasoline having an A.S.T.M. mid-boiling (50%) point of 310 F.'or higher will not be subject to stalling. Al-. though this may be 'thecase foragiven series of gasolines, however, it is not the sole and controlling factor.

- Gasolines of higher-mid boiling point but 'a low initial the art, and it is a commercially-available material.

Theamount of 2-pyrrolidone that is added to the motor gasoline will vary between about 0.005 percent and about 0.5 percent, by weight, of the gasoline. In preferred practice, amounts varying between about 0.01 percent and about.0.05 percent, by weight, are used.

The antistall additive of the the gasoline along with other antistall addition agents or with other additives designed to impart other improved propertiesthereto. Thus, anti-knock agents, pre-ignition inhibitors, antirust agents, metal-deactivators, dyes, antioxidants, detergents, etc., may be present in the gasoline. Also, the gasoline'may contain a small amount, from about 0.01 percent to about 1 percent, by weight, of a sllitabi6.0l1 S,'-f0l example, include Coastal'and Mid-Continent distillate oils having viscosities withi n the range of from about 50 to about 500 S.U.S.-at F. Synthetic oils, such: as diester oils, 'polyalkyleneglycols, silicones, phosphate esters, polypropylenes,polybutylenes and the like may also be used. 7

. The following example is for the purpose of illustrating this invention and demonstrating the effectiveness thereof."

The ability of an additive strated in the following test:

to inhibit icing is demonon a standard 1953 HillmamMinxengine. The'engine was connected to a 7.5 horsepower induction motor and operated under load at 2800 rpm. This was'equivalent to driving at about 40 miles per hour.

The Solex carburetor was especially prone to icing on its spraying well which is located in the center of the carburetor throat. The spraying well is a cylindrical metal tube with apertures through which a fuel-air mixture is sprayed into the carburetor throat. fuel refrigerates thespraying well.

As ice formed on the well it restricted theflow. of air through the carburetor and caused a drop in pressure. This pressure change was recorded by a manometer coninvention may be usedin Evaporation of the; Q

2. I.) nected above and below the point of ice deposition. Temperatures at this point were measured by a thermocouple attached to the well. The entire carburetor was enclosed in an asbestos chamber that was connected to an ice tower. Air at 34-37 F. and 90100 percent relative humidity was passed through the carburetor at constant velocity.

In conducting a test the engine was first run until the spraying well reached an equilibrium temperature of about 20-25 F. The fuel flow was then stopped and the engine was driven by the induction motor until the spraying well reached 45 F. (warm ambient air was admitted to the carburetor during this period). Fuel flow was now restored to the engine and the run was started. As the engine operated under load, ice deposited on the spraying well. The pressure drop across the ice formation was recorded at one-minute intervals for 20 minutes. Several tests were made on each fuel blend and the results were averaged.

A fuel rating was obtained by using these pressure readings to calculate the percentage of the carburetor throat area that would be blocked with iceafter 20 minutes. The percent of annular area in the carburetor that is blocked by ice determines the amount of pressure drop ,cross the annular opening in any given installation. Thus, for each carburetor, the amount of throat area blocked by ice is related to the amount of pressure drop above and below the point of ice deposition. The relationship between pressure drop and area blocked was determined to calibrate the carburetor, as follows:

A series of flanged cylinders were prepared, which.

fitted over the emulsion tube. and blocked a portion of the annular opening. Each tube hada different, but known size flange. Thus, it was known what fraction of the annular area was blocked by each flange. The engine was operated with a flanged cylinder in the carburetor and the amount of pressure drop was noted and recorded. This operation was repeated with each flange.

From the data, thus obtained, the relationship between pressure drop and amount of throat area blocked was plotted. Then, when runs were made using blank fuel or inhibited (test) fuel, but with no flanged inserts in the carburetor, the throat area blocked by ice was determined from the amount of pressure drop. The area blocked after the 20-minute run is calculated from the summation of the one-minute observations.

It will be appreciated, of course, that calibration curves will vary with each carburetor, but any carburetor can be readily calibrated as aforedescribed. .As is the case in many test procedures, results can vary from time to time, because of slight variations in test conditions, vapor pressure of fuel, and even techniques'of individual operators.

be run. This provides a reference point, so that even if values determined may not be finite, comparison of a test fuel result with the result on the blank fuel gives a positive order of magnitude, i.e., one can say for example that an additive cut the amount of ice formation by'some certain percentage.

The test gasoline was a blend, by volume, of 66 percent catalytically cracked gasoline, 2 percent natural gasoline, 12 .percent benzene, 8 percent toluene, and 12 percent butane. It had an A.S.T.M. boiling range of 80 F. to 394 F., with a mid-boiling point of 200 F.

Blends of Z-pyrrolidone in test gasoline were subjected to the Hillman-Minx engine test. Pertinent data and test results are set forth in Table I.

Table 1 Percent annular 2-pyrrolldone area blocked with ice concn, wt. percent 0.00 (blank); 40 .02 28 0.00 (blank)-.. 32 0.04 13 0.05 13 0.00 (blank) 40 0.10 4.5 0.25 0.7

2,919,684 Carr Thus, each day a testrun is made, a blank fu el should I It will be apparent from the data in Table I, that the additive of his invention is an effective antistall additive for gasoline. At higher concentrations used, almost percent reduction in icing is effected. 7 Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such variations and modifications are considered to be within the purview and scope of the appended claims.

What is claimed is:

1. A motor gasoline containing a small amount, suflicient to inhibit icing, of Z-pyrrolidone.

2. A motor gasoline containing between about 0.005 gercent and about 0.5 percent, by weight, of 2-pyrrolione.

References Cited in the file of this patent UNITED STATES PATENTS Nelson Mar. 6, 1956 Duncan et al Mar. 5, 1957 Jan. 5, 1960 OTHERREFERENCES Petroleum Refining with Chemicals, Kalichevsky and 7 Kobe, Elsevier Pub. Co., 1956, p. 9180. 

1. A MOTOR GASOLINE CONTAINING A SMALL AMOUNT, SUFFICIENT TO INHIBIT ICING, OF 2-PYRROLIDONE. 